People who mined, held for a bit, and sold, could have made some MASSIVE profits.
I don't sell anything, I mine and hold. And hold. And hold. I'm waiting for a massive gain or nothing at all. It's pointless to me to mine and sell immediately for like what, $20/day profit and dropping every couple weeks?
But as odolvlobo points out very clearly, the gains come from
holding those coins, not from mining them.
And since the majority buy their rigs in fiat, it begs the question of why one wouldn't just buy and hold bitcoin, as opposed to mining.